US3825306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential-lock type device for a motor vehicle
Assignee: TDK Micronas GmbH
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Filing: 1973-03-19
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Granted: 1974-07-23
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Expires: 1993-03-19
Abstract
Abstract There are disclosed arrangements combined with known anti-skid systems that will prevent spinning of one drive wheel while the other drive wheel is stationary due to differential gearing. This is accomplished by providing a threshold circuit responsive to excess acceleration of the spinning wheel, in addition to the normal acceleration threshold circuits of an anti-skid system, to cause brake pressure to be applied to the wheel brake cylinder of the spinning wheel. The additional threshold circuit is placed in operation by the vehicle driver.
Inventors
- 👤 W Fink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:44
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/48; B60T8/4809; B60T8/17; B60T8/175; B60T2201/00; B60T2201/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
300 words
A differential-lock type device for a motor vehicle comprising: an axle including differential gearing for driving a pair of road wheels; a wheel brake cylinder coupled to each of said pair of wheels; an anti-skid system coupled to at least one of said pair of wheels; and an arrangement coupled to said anti-skid system responsive to acceleration of said one of said pair of wheels exceeding an acceleration threshold greater than all acceleration thresholds normally employed in said anti-skid system to apply brake pressure to said wheel brake cylinder associated with said one of said pair of wheels to prevent spinning of said one of said pair of wheels; said arrangement being activated by a driver of said motor vehicle to cause said arrangement to be responsive to said acceleration exceeding said acceleration threshold greater than said acceleration thresholds normally employed in said antiskid system; and said anti-skid system including a master cylinder, a hydraulic brake pressure medium accumulator, a hydraulic brake pressure medium reserve tank, a combined separating valve and a hydraulically controlled displacement piston, said separating valve normally connecting said master cylinder to said wheel brake cylinder of said one of said pair of wheels, a first normally open electromagnetic valve connecting said accumulator to said displacement piston, a second normally closed electromagnetic valve connecting said displacement piston to said reserve tank, and first electronic circuitry coupled to said one of said pair of wheels and said first and second valves to produce usual antiskid control signals in response to the value of a wheel acceleration signal relative to a first acceleration threshold and a deceleration threshold, said anti-skid control signals controlling said first and second valves and, hence, said combined separating valve and displacement piston to prevent the skidding of said one of said pair of wheels.
Claim 2
Dependent Claim
300 words
A differential-lock type device for a motor vehicle comprising: an axle including differential gearing for driving a pair of road wheels; a wheel brake cylinder coupled to each of said pair of wheels; an anti-skid system coupled to at least one of said pair of wheels; and an arrangement coupled to said anti-skid system responsive to acceleration of said one of said pair of wheels exceeding an acceleration threshold greater than all acceleration thresholds normally employed in said anti-skid system to apply brake pressure to said wheel brake cylinder associated with said one of said pair of wheels to prevent spinning of said one of said pair of wheels; said arrangement being activated by a driver of said motor vehicle to cause said arrangement to be responsive to said acceleration exceeding said acceleration threshold greater than said acceleration thresholds normally employed in said antiskid system; and said anti-skid system including a master cylinder, a hydraulic brake pressure medium accumulator, a hydraulic brake pressure medium reserve tank, a combined separating valve and a hydraulically controlled displacement piston, said separating valve normally connecting said master cylinder to said wheel brake cylinder of said one of said pair of wheels, a first normally open electromagnetic valve connecting said accumulator to said displacement piston, a second normally closed electromagnetic valve connecting said displacement piston to said reserve tank, and first electronic circuitry coupled to said one of said pair of wheels and said first and second valves to produce usual antiskid control signals in response to the value of a wheel acceleration signal relative to a first acceleration threshold and a deceleration threshold, said anti-skid control signals controlling said first and second valves and, hence, said combined separating valve and displacement piston to prevent the skidding of said one of said pair of wheels.
Claim 3
Dependent Claim
109 words
A device according to claim 1, wherein said arrangement includes a solenoid winding for each of said first and second valves, an electric circuit inteRconnecting said windings, and second electronic circuitry coupled to said first electronic circuitry and said electric circuit to produce a spinning control signal when the value of said wheel acceleration signal exceeds a second acceleration threshold greater than said first acceleration threshold, said spinning control signal controlling the current flow in said electric circuit to control the operation of said first and second valves and, hence. said combined separating valve and displacement piston to prevent the spinning of said one of said pair of wheels.
Claim 4
Dependent Claim
26 words
A device according to claim 2, wherein said arrangement is activated by a driver of said motor vehicle closing a switch connected in said electric circuit.
Claim 5
Dependent Claim
96 words
A device according to claim 2, wherein said electric circuit includes both of said solenoid windings, a source of voltage, a normally open mechanical switch, and a normally closed electrically controlled switch, said windings, said source and said swtich being connected in a series circuit; and said second electronic circuitry includes a first threshold circuit having said second acceleration threshold and its output coupled to said electrically controlled switch to control the current flow in said electric circuit, said first threshold circuit being coupled to said first electronic circuitry to respond to said wheel acceleration signal.
Claim 6
Dependent Claim
199 words
A device according to claim 4, wherein said first electronic circuitry, includes first means coupled to said one of said pair of wheels to produce said wheel acceleration signal, a second threshold circuit having said deceleration threshold coupled to said first means to produce one of said anti-skid control signals when said acceleration signal is less than said deceleration threshold, said one of said anti-skid control signals activating both said first and second valves to their switched position, namely, to open said first valve and to close said second valve, to actuate said combined separating valve and displacement piston to prevent the skidding of said one of said pair of wheels, a holding circuit coupled to said second circuit to maintain said first and second valves in their switch position, and a third threshold circuit having said first acceleration threshold coupled to said first means and said holding circuit to produce another of said anti-skid control signals when said acceleration signal is greater than said first acceleration threshold, said another of said anti-skid control signals deactivating said holding circuit and thereby return said first and second valves and said combined separating valve and displacement piston to their normal position.
Claim 7
Dependent Claim
16 words
A device according to claim 5, wherein said first circuit is coupled to said first means.
Claim 8
Dependent Claim
22 words
A device according to claim 6, wherein said arrangement is activated by a driver of said motor vehicle closing said mechanical switch.
Claim 9
Dependent Claim
146 words
A device according to claim 7, wherein when said mechanical switch is closed prior to said first threshold circuit producing said spinning control signal said first and second valves are changed to said switched position to move said combined separating valve and displacement piston to interrupt the connection between said master cylinder and said wheel brake cylinder and expand the volume of a pressure medium connection to said wheel brake cylinder, and after said first threshold circuit produces said spinning control signal the current flow in said electric circuit is interrupted by said electrically controlled switch, said first and second valves return to their normal position and said combined separating valves and displacement piston returns to its normal position to reconnect said wheel brake cylinder to said master cylinder and apply brake pressure to said wheel brake cylinder due to said driver actuating said master cylinder.
Claim 10
Dependent Claim
26 words
A device according to claim 8, wherein said second acceleration threshold is equal to +1.0 g, where g is equal to 32.1578 feet per second squared.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |